cant be much, you would hate to wreck an engine cause some dumb PO put the wrong gasket on
here is how it looks…I have a box of them all sorts, only 1 was right for my 420G (same gasket)
take all the parts out of the housing and examine them for PO bodge
Hi all,
Thank you for all the pointers, really appreciate the help with this issue.
Attached the pics from my car: the engine block end with the gasket (which seems to me the right one), the housing, and the pressure relief valve as it came out. The rubber O ring for the canister was undamaged and snugly into its groove.
I see nothing wrong.
Next thing I will do is see if I can blow through the oil return line into the sump and maybe see if I can do same with the oil passage into the block.
Other than that I am out of ideas…
Best
Paul
Looks right , I would try and blow air down the return hole in the block !
Must be a blockage in the line some where , have you checked the balance valve 15 ?
Thanks Ian. Which is the return hole in the block and what is the balance valve - or is it no 15 in the parts picture? What do I check for with the latter?
Paul
Yes it’s 15 , not sure what it’s for , on some housings it’s marked up as a drain .
The top most hole is the return , that feeds in to the main oil way that runs the length of the engine !
I would pump compressed air into that oilway,
and also remove an oil galley plug from the side of the block, and pump air in there
you should hear it bubbling in the cam cover by looking in the filler hole
never actually heard of this problem in all my years on JL
I was of the view, (but open to be skooled) that if excessive OP is generated, the bypass valve should dump some of its load back into the sump, so some hole or passage must be blocked, either by debris, or an improperly positioned oilway hole, or defective valve
I am very hesitant to suggest this, but If you temporarily gutted the relief valve, and left out the filter element, that may prove out faulty parts (after an air thru oilways test passed ok)
I shall try to find a compressor…
It IS an odd issue, I still can’t get my head around it, but it has been with a french ‘countryside’ Renault garagiste for the last six months who has tried to fix this and re-used all the old gaskets - which I have now replaced - , so who knows what has happened to it.
I have tried it without a filter, but not yet without a relief valve. But as suggested, I’ll see if I can get some results blowing some air into the various holes…
Tony, you say: ‘remove an oil galley plug’… is that the plug next to the oil return hole in the block with a screw slot in it, or something else? And if the latter, where can I find those?
Paul
A foot pump would do , just to see if it pressurises , oil gallery plugs are all the way along the block
Awesome! Thank you.
No time today, but hopefully tomorrow.
Best
Paul
P.s. if the oil feed goes into the block in the middle of the six ‘vertical’ oil feeds… then either all six (or at least a large number) are blocked, or the blockage is just before it goes into the main gallery… that I can see by poking around in that hole with a metal wire…
No…all along the side of the block, you will find a row of short bolts, 3/4" I think, maybe 13/16"
These are oil gallery plugs, such things as OP idiot lights are screwed into them in XJ engines
as can be understood from their name, they tap right into the main oil gallery
Just saw another pic…
oil-pump.jpg
Paul
given where ur at, I would be hesitant to run the engine at all, however, if you remove one of those plugs, and have an assistant start the engine, pressurised oil should spurt out
I would not run the engine for more than 3secs
Hmm, too late. I have run it twice for about 30 seconds already, but won’t again.
One by one I’ll take off the two end plugs and blow air in To see if that comes through.
I’ll also see if the return to the sump is blocked.
I’ll repost back on my findings probably tomorrow or day after.
Paul
Just thought of a way to check the housing , if you clean it up so tape sticks to the face , tape a pipe in each side, and blow down one , and hold your finger over the other , your need the filter body on , not the filter , that should tell you if the housing is ok , if air passes , oil will !
Right … I broke it. There was a small dent in the housing outer lip and whilst trying to get that back to where it belonged, the lip broke off. 
Anyone got a spare filter housing?
In the meantime, as I had the housing off, I put the canister back on with nothing in it and screwed the bolt tight. I then discovered I could still jiggle and move/turn the canister! So even though the bolt was screwed in to its maximum, there was no pressure holding the canister to the rubber O ring! I can only surmise that the little ding prevented the canister from moving and turning when I had it on the car, but with that removed, it became apparent the bolt was too long/its thread too short. That meant oil would come out before the pressure relief valves started operating.
I also blew through the oil passages in the block as well as into the sump and those are clear.
So, I just need a new housing and a proper length bolt, and then I hope I’m back in business.
… anyone?
Paul
Depends where you are. If you modify your avatar with your country flag then people in the country/area can reply.
Ok, good tip, thank you, done.
Based in London, but I will pay for postage for a good one.
Paul
this,
how much too “long” is the bolt?
That is an odd situation
there is a special seal between the bolt and external metal cannister, which compresses
They leak there if the seal is not fitted
I have a couple of damaged housings!
They are very vulnerable when pulling an engine, should be removed 1st
It is possible I may be able to contact someone in the UK that has one, he sold used MKX parts at one time, UK Ebay will turn one up, but whether it is damaged?
The filter head must point straight down, which rules out various other saloons
I am going to reluctantly suggest you trial fit the cannister in the housing, unless the O-ring is exposed, it may still be functional, (after carefully cleaning up any inside ding)
Clearly this is not wholly desirable, but I think it is worth examining and trying.
The canister rim touches the O ring seal in the housing, but there is no pressure. We are talking mm’s here and I think a couple of washers at the end of the bolt might recover enough thread to tighten properly against the top seal.
The seal on the bottom of the canister where the bolt goes in is new, and fine, but I guess also no pressure there with the bolt too long and running out of thread at the top.
I can only surmise the bolt is not original OR the frenchman shaved some off the canister, thinking the rim was warped or something… .
The O ring is exposed for about 1.5 cm, so I think oil will seep through there.
IMG_8143.JPG
I’ll await a new housing. [sigh]
Paul
